Multiple sensor input data synthesis

ABSTRACT

New systems and methods are hereby provided that inherently and naturally resolve the challenges of synthesizing coordinated inputs from multiple cameras. For example, a multi-sensor mediator may collect the input data from multiple sensors, and generate a composite signal that encodes the combined data from the different sensors. The multi-sensor mediator may then relay the composite signal to a sensor controller, as if the signal were coming from a single sensor. A computing device that receives the input from the sensor controller may then generate an output based on the composite signal, which may include processing the composite signal to combine the separate signals from the different sensors, such as to provide a stereo image output, for example. The multi-sensor mediator makes such an output possible by ensuring coordinated input and processing of the input from the multiple sensors, for example.

CROSS-REFERENCE

This application is a continuation of and claims priority under 35U.S.C. §120 to U.S. patent application Ser. No. 11/818,737, filed onJun. 15, 2007 and titled “Multiple Sensor Input Data Synthesis,” thedisclosure of which is incorporated by reference in its entirety herein.

BACKGROUND

Image sensors such as cameras and webcams are becoming ever more widelyused in association with computing devices. There is a growing interestin using multiple image sensors at one time in the same setting. Thiscan allow for the same scene to be captured from multiple vantagepoints, allowing a user to alternate between vantage points in a webcamexperience, a game, or a video playback, or allowing multiple images tobe combined to create a three-dimensional viewing experience, such asfor a movie, a virtual reality application, or a webcam interaction.

However, providing two or more image sensor inputs simultaneously andsynchronously over a single interface, together with control output tomultiple image sensors, poses substantial challenges for the hardwareand/or software that handles the input and output data. For example, onetypical arrangement may include multiple universal serial bus (USB)webcams that are all meant to stream image data simultaneously to a hostcomputer. A typical way to make this arrangement work may be to havemultiple USB webcam control circuits, one connected to each of the USBwebcams, with all the USB webcam control circuits connected to anembedded USB hub.

However, such an implementation would be costly for the hardware andcomplex for the software. For hardware, one webcam controller circuitfor each webcam, plus an embedded USB hub, adds up to a significantcost. For software, each webcam controller would appear as a separateUSB device, which would complicate device setup in the operating systemfor the user, and add processing overhead if further image processing isrequired on multiple input video streams. Each of the webcam controllercircuits would have to negotiate with the host controller for its ownUSB bandwidth, reducing the efficiency of the USB bandwidth andpreventing any guarantee of equal USB bandwidth among the differentwebcams. In some cases, one or more of the webcams might not beallocated any bandwidth at all. Unallocated or low bandwidth means noguarantee of frame to frame synchronization between the signals from thedifferent webcams. Lack of frame synchronization would give rise to acatastrophic error mode if the software application requiredframe-synchronized input video from the different image sensors, such asfor stereo combination of the webcam images, which would then beimpossible.

The discussion above is merely provided for general backgroundinformation and is not intended to be used as an aid in determining thescope of the claimed subject matter.

SUMMARY

New systems and methods are hereby provided that resolve the challengesof synthesizing coordinated inputs from multiple cameras. Oneillustrated embodiment provides for a method for processing coordinatedinputs from multiple sensors. The method includes receiving signalsrepresenting a plurality of sensor inputs from a plurality of sensors.The method further includes generating a composite signal that encodesthe plurality of sensor inputs from the plurality of sensors. The methodalso includes providing the composite signal to a sensor controller. Themethod further includes generating an output based at least in part onthe composite signal.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter. The claimed subject matter is not limited to implementationsthat solve any or all disadvantages noted in the background.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B depict computing devices with multiple sensors,according to an illustrative embodiment and depicted in an illustrativeuser context.

FIG. 2 depicts a method for multiple sensor input data synthesis,according to an illustrative embodiment.

FIG. 3 depicts a method for multiple sensor input data synthesis,according to an illustrative embodiment.

FIGS. 4A and 4B depict multi-sensor input management systems comprisingmulti-sensor mediators, according to illustrative embodiments.

FIG. 5 depicts a multi-sensor input management system comprising amulti-sensor mediator, according to an illustrative embodiment.

FIG. 6 depicts timing diagrams for sensor input signals and amulti-sensor input composite signal, according to an illustrativeembodiment.

FIG. 7 depicts a computing environment that comprises devices accordingto an illustrative embodiment and enables methods according to anillustrative embodiment.

DETAILED DESCRIPTION

FIGS. 1A and 1B depict computing systems 100A and 100B that each enablea method for processing coordinated inputs from multiple image sensors101, according to an illustrative embodiment. Computing systems 100A and100B may be illustrative of embodiments that include various hardwarecomponents involved with computing, input, output, and associated tasks,and executable instructions configured to be executable by computingsystems, and contexts that enable method embodiments, for example. Thefollowing discussion provides further details of various illustrativeembodiments. While certain illustrative system components and aspectsinvolved with computer-implemented methods are included in this and thesubsequent figures, they are intended not to indicate any limitations,but rather to provide an illustrative example the variety and broadermeaning provided in the discussion and claims herein.

Computing systems 100A, 100B each includes a plurality of cameras 101,102, connected to a multi-sensor mediator 103, which is connected to animage sensor controller 105. Each of these connections, and additionalconnections discussed below associated with computing systems 100A,100B, enables communication of signals between the components thusconnected. Cameras 101, 102 are image sensors that may be web cameras(“webcams”) or other video cameras, for example. Cameras 101, 102 may beembodied as video graphics array (VGA) complementarymetal-oxide-semiconductor (CMOS) image sensors, in this illustrativeembodiment. Other embodiments may also be used, such as Super VGA (SVGA)or Extended Graphics Array (XGA) image sensors, for example.

In this embodiment, webcams 101, 102 may image a user positioned infront of video monitor 121 and cameras 101, 102, such as users 98, 99,enabling users 98 and 99 to hold a video conference call with eachother. Image sensor controller 105 is connected to a system bus 111 ofthe computing system, which has several other computing componentsconnected to it, such as system memory 113, processing unit 115, networkinterface 117, and output interface 119. Many of these components may beincluded within a single computing device 110, or they may bedistributed through other parts of computing systems 100A, 100B or othercomputing resources connected by a network or other communicativeconnection, in different embodiments. Output interface 117 may beconnected to the Internet 120 and/or to other networks. Output interface119 may provide video output to video monitor 121 and audio output toaudio speakers (not depicted), for example. These and other potentialcomponents of computing systems 100A, 100B are described in greaterdetail in association with FIG. 8, below.

Computing system 100A may thereby enable images of user 98 captured bycameras 101, 102 of computing system 100A to be transmitted to computingsystem 100B and provided as an output on video monitor 121 of computingsystem 100B, while computing system 100B may enable images of user 99captured by cameras 101, 102 of computing system 100B to be transmittedto computing system 100A and provided as an output on video monitor 121of computing system 100A, for example. Video monitors 121 therebyprovide an output based ultimately on the composite signal frommulti-sensor mediator 103 that reproduces to some degree the imagesoriginally received from cameras 101, 102. Such reproduction mayincorporate information on a single subject imaged by more than onecamera, such as by providing a stereo representation, for example.

Multi-sensor mediator 103 serves as an intermediary component betweencameras 101, 102 and image sensor controller 105. Multi-sensor mediator103 may be embodied in any of a variety of forms, such as afield-programmable gate array (FPGA), a complex programmable logicdevice (CPLD), a microcontroller, a microprocessor, a digital signalprocessor (DSP), or a component of the image sensor controller 105, forexample. Multi-sensor controller 103 enables methods of coordinating orsynthesizing the data input from multiple sensors, such as cameras 101and 102. One such method is illustratively depicted in flowchart 200 asdepicted in FIG. 2. As indicated in flowchart 200, multi-sensor mediator103 is configured to receive signals representing a plurality of sensorinputs, such as signals having an image-encoding format and representinga plurality of images, from a plurality of sensors, such as cameras 101and 102, as in step 211. As further indicated in flowchart 200,multi-sensor mediator 103 is further configured to generate a compositesignal that encodes the plurality of sensor inputs from the plurality ofsensors, such as by representing a combination of the images from thecameras 101 and 102, as in step 213. Multi-sensor mediator 103 isfurther configured to provide the composite signal to a sensorcontroller, such as image sensor controller 105, as in step 215; and togenerate an output based at least in part on the composite signal, suchas the video images provided on video monitors 121, as in step 217.Different embodiments of the process of flowchart 200 may includeadditional steps, such as steps for the sensor controller to process thecomposite signal and relay it to other system elements, prior toultimately generating an output. For example, the sensor controller maycompress the image information from the composite signal and send acompressed signal to other system elements, and other system elementsmay perform actions of decompressing the image and/or performing othermodifications to the image prior to generating a video output on a videomonitor.

FIG. 3 depicts a schematic representation 300 of the images encoded bythe signals from cameras 101 and 102 being used to generate a singlecomposite signal that encodes the multiple images. A time-ordered seriesof images 301 may be recorded by camera 101, which provides a signalrepresenting those images to multi-sensor mediator 103. Another,simultaneous time-ordered series of images 302 may be recorded by camera102, which provides a signal representing those images to multi-sensormediator 103.

Multi-sensor mediator 103 may then combine or synthesize thesimultaneous signals, or data streams, from cameras 101 and 102. Oneillustrative way of combining the data streams from the two separatecameras is by combining the images from the multiple cameras for asingle time frame into a single image, so that the signal (i.e. datastream) provided by multi-sensor mediator 103 provides a single, largerimage for each time frame.

As depicted in FIG. 3, multi-sensor mediator 103 provides an outputcomposite signal (directed to the sensor controller 105, not depicted inFIG. 3) that encodes a time-ordered series of images, each of whichincludes encodes the images received from cameras 101, 102 at one timeas one composite image. As depicted in the illustrative example in FIG.3, the composite images 305 each include the original images 301, 302spaced horizontally adjacent to each other.

For example, in one illustrative embodiment, the cameras may eachprovide an output encoding a time-ordered sequence of images of 640 by480 pixels, and the multi-sensor mediator 103 may combine these multipleimage streams into a single time-ordered stream of images of 1280 by 480pixels, consisting of the images from the two original image streamsspaced horizontally adjacent to each other. Any other pattern forencoding the multiple sensor inputs into a single composite output mayalso be used, such as spacing the images vertically adjacent to eachother, or interspersing the original images in separate sections bylines or pixels, for example.

Additionally, while two cameras 101, 102 and two sensor input streams301, 302 are depicted in the illustrative embodiments of FIGS. 1 and 3,other embodiments may include any number of cameras or other sensors,and any number of sensor input signals. For example, a time-slicephotography arrangement, an interferometric or segmented telescope, or apositron emission tomography (PET) scintillator, for example, mayinclude tens, hundreds, or thousands of imaging elements with shared orassociated imaging fields, and their inputs may advantageously becombined by a sensor intermediary device into a composite signal that isthen provided to a sensor controller.

The single composite signal that encodes a combination of the sensorinputs may then be provided by multi-sensor mediator 103 to the sensorcontroller 105 (as in FIG. 1) as if it were the output of a singlesensor. The output of the sensor controller 105 to the core componentsof the computing device 110, such as processing unit 115, may then beprocessed to recover the information from the original, separate sensoroutputs. This is in stark differentiation from previous systems, whichtypically include a sensor controller immediately connected to eachsensor and relaying the signals from its own sensor, with the varioussensor controllers all connected to a single hub, such as an n-portUniversal Serial Bus (USB) hub, such that the sensor controllers competewith each other for bandwidth, synchronization of the multiple sensordata streams at the processing unit is difficult if not impossible, andone or more sensor controllers may be denied any bandwidth at all forsignificant periods of time, potentially causing catastrophic failure ofthe signal processing from all the sensors. In contrast, themulti-sensor mediator 103 provides performance advantages such asensuring that the inputs from the various sensors at the same time areinherently delivered to the processing unit of the computing devicetogether and with their time synchronization preserved, according to thepresent illustrative embodiment.

Advantages such as those described above may make the difference inenabling successful implementation in applications that require anear-real-time, reliably synchronous stream of multiple images, such asgenerating a video output with stereo projection, as a time-orderedsequences of images based on the composite signals. The stereorepresentation may be provided by comparing the image components fromthe different sensors to evaluate distances of different objects fromthe cameras or other sensors, and represent the objects in differentformats in the output images as a function of their distances from thecameras or other sensors, in this illustrative embodiment. The stereorepresentation of the output images may combine original images receivedby two, three, four, or any other number of sensors.

As an example, computing systems 100A, 100B may distinguish betweenforeground objects and background objects in the images originallyreceived from cameras 101, 102, and incorporate distinctions between theforeground objects and the background objects in the output imagesprovided in video monitors 121. In one illustrative example, thesedistinctions between foreground and background objects may take the formof the output images comprising the foreground objects combined with abackground image derived from a source other than the images originallyreceived from the image sensors. In other words, the components of theoriginal images determined to constitute background objects may beremoved from the images and replaced with a freely selected background,such as an exotic location or an animated scenario, for example. Theinformation from the composite signal may also be subjected to patternrecognition mechanisms, such as face recognition applied to theforeground image of a user and/or other images corresponding to humanfaces that occur in the input images encoded in the composite signal.The imported background and other artificial image components may beselected based at least in part on the results of the face recognition,such as to automatically provide image component options previouslyselected by a user for output images of the user, in one illustrativeembodiment.

The stereo representation may also be provided by using an image sensorto capture a scene illuminated with light of a first polarization angleand from another sensor capturing the same scene using an illuminationsource with light of a second polarization angle, such as a polarizationorthogonal to the first polarization, in an illustrative embodiment. Inother illustrative embodiments, the different image components from thedifferent sensors may be captured by different camera systems which usedifferent wavelengths of light to illuminate the scene, for example,with either one wavelength or several wavelengths from across thevisible spectrum assigned uniquely to the image components from each ofthe cameras or other sensors. Any number of different cameras may beused to capture original images at any number of different polarizationsor wavelengths. The stereo projection, with the image components ofdifferent cameras provided in different formats such as differentpolarizations or wavelengths, may be used to render an output image witha three-dimensional appearance, such as by maintaining the binoculardepth perception captured by the input cameras 101, 102 in the outputimage, using a mechanism of differentially distributing the binocularinputs as binocular outputs directed in separate outputs to each of theuser's eyes, for example. The binocular outputs may be provided, forexample, by active monitoring of the user's gaze and active projectionof the differential images into the user's eyes; by binocular videooutput goggles or a binocular video output scope; or by binocularfilters worn or otherwise used by the user, configured to filter thepolarizations, wavelengths, and/or other mechanisms of differentialoutput used to maintain the binocular images from the multiple inputcameras.

FIG. 4A depicts multiple sensor system 400 with multi-sensor mediator403 in communicative connection with two image sensors 401, 402 and asensor controller 405 according to one illustrative embodiment.Multi-sensor mediator 403 may be embodied as an integrated circuit, forexample. In this embodiment, the multi-sensor mediator 403 combines thesignals from the image sensors 401, 402 into a composite signal andassociates the composite signal with a single device address, indicatedas x00, prior to providing the composite signal to the sensor controller405. The device address can include any indicator of a particular deviceor element that facilitates communicating with a particular device, indifferent embodiments. In one illustrative embodiment, the single deviceaddress for the multi-sensor mediator 403 may be a slave address in theInter-Integrated Circuit (I²C) bus protocol, to which the sensorcontroller 405 directs its instructions, while the sensor controller 405may have an I²C master address to which the multi-sensor mediator 403directs the composite signal, for example. The multi-sensor mediator 403may then serve as a bus switch, having both a slave node interface and amaster node interface, and relay the instructions it receives at thesingle I²C slave address to the separate sensors 401, 402 andpotentially additional sensors, relaying the same message to slaveaddresses associated with each of the sensors, as depicted in FIG. 4A.

FIG. 4B depicts multiple sensor management system 450 according toanother embodiment in which image sensors 451 and 452 have differentsettings, and multi-sensor mediator 453 is capable of receivingdifferent sets of instructions from sensor controller 455 addressed toindividual image sensors, and relaying those individual instructions tothe particularly addressed image sensors. In one illustrativeembodiment, this may be accomplished by providing instructions fromsensor controller 455 addressed to a single I²C slave addresscorresponding with multi-sensor mediator 453, but with thoseinstructions encoding different sets of instructions indicated, as withthe illustrative address markers x01 and x02 in FIG. 4B, for applicationto a subset of the available sensors. Multi-sensor mediator 453 isconfigured to interpret and separate the instructions with the distinctaddress markers into different sets of instructions that it respectivelysends to different I²C slave addresses corresponding with one or moresubsets of the sensors connected to it, where each subset may includeone or more individual sensors. This mode of communication between thedifferent components thereby enables separate instructions to beprovided to each of the available sensors, enabling additionalcapabilities for controlling the collection of sensor inputs.

In another illustrative embodiment, image sensor controller 455 may beconfigured to communicate to multi-sensor mediator 453 a request for aresolution level equivalent to a multiple of the resolution of anindividual one of the image sensors 451, 452. For example, theindividual image sensors 451, 452 may each have the standard VGAresolution of 640 by 480 pixels, and the image sensor controller 455 maybe configured to send a request to the multi-sensor mediator 453 for aresolution level of either 640×480 or 1280×480 pixels, corresponding toa multiple of either one times, or two times, the resolution of one ofthe individual image sensors 451, 452. The multi-sensor mediator 453 mayalso be further configured to provide an appropriate signal back toimage sensor controller 455 that is responsive to the requestedresolution. That is, multi-sensor mediator 453 may be configured to sendeither the original signal from a single one of the image sensors,representing images from just that one image sensor, if the image sensorcontroller requests a resolution level equivalent to one of the imagesensors; while multi-sensor mediator 453 is also configured to send acomposite signal, representing a combination of the images from a numberof the image sensors having a combined resolution equivalent to theresolution level requested by the image sensor controller 455, if theimage sensor controller 455 requests a resolution level that is higherthan the resolution of one of the image sensors.

For instance, if the image sensor controller 455 sends a request for aresolution level of 1280×480, which is higher than the resolution of asingle image sensor and is equivalent to the resolution from two imagesensors, such as image sensors 451 and 452, the multi-sensor mediator453 is configured so that it may provide a composite signal thatstitches together or combines the images from the two image sensors 451and 452 in response to that resolution request. The requested resolutionmay also be a larger multiple of the resolutions of the individual imagesensors. For example, the image sensor controller may send a request fora resolution of 1920×480 or 640×1340, for example. In these cases, wherea third image sensor is also communicatively connected to multi-sensormediator 453, multi-sensor mediator 453 may be configured to generate acomposite image that stitches together the images from three imagesensors, for a combined resolution of 1,920 by 480 pixels, or 640 by1,340 pixels, as the case may be. The software hosted on a computingdevice to which image sensor controller 455 is connected may then beconfigured to translate the composite image to gain the information fromeach of the three image sensors.

The image sensor controller 455 may also send requests for any otherlevel of resolution, equal to the multiple of two, three, four, or moresensors, which may include sensors of varying resolution, and mayspecify a certain pattern for how that resolution is encoded, and themulti-sensor mediator may respond by providing a composite signal ofthat resolution. This may also include the image sensor controller 455sending a request for a resolution that does not match an integermultiple of the resolution of the individual sensors connected withmulti-sensor mediator 453, and multi-sensor mediator 453 may respond bysending a composite signal that includes partial information from one ormore of the sensors connected to it, in order to match the requestedresolution from the image sensor controller 455.

In any of these embodiments, the sensor controller may receive thecomposite signal from its multi-sensor mediator, where the compositesignal incorporates combined information from the sensors. The sensorcontroller in turn may provide a processed signal based on the compositesignal to other computing system components, such as a processing unit,enabling output to be generated based at least in part on the compositesignal. The processed signal may take the form of a Universal Serial Bus(USB) protocol signal, in one exemplary embodiment, where the sensorcontroller acts as a single, sole USB device that is registered to theoperating system of the computing system, thereby inherently deliveringthe inputs from the multiple sensors in a synchronous and coordinatedsignal, rather than having multiple sensor controllers associated witheach of the sensors competing for USB bandwidth. The USB bandwidth isthereby more efficiently utilized because of reduction of transferoverhead, and bandwidth allocated to the one registered sensorcontroller will be shared equally among all of the associated imagesensors, in this illustrative embodiment.

Additional functions may also be introduced by using the multi-sensormediator with multiple cameras. For example, another function that maybe performed is exposure banding. In exposure banding, two or morecameras use different levels of light exposure for recording images. Thedifferent images may then be compared, and bits or other portions of theoriginal images may be selected for having the best light exposure. Thismay be used, for example, if a relatively dimly lit subject is in frontof a relatively harshly lit background. In this case, portions of theimages dealing with the foreground subject may be taken from one camerathat is relatively overexposed, and portions of the images that containthe background may be taken from another camera that is relativelyunderexposed. These foreground and background image portions may then becombined into a single image in which the foreground subject and thebackground are both properly exposed. Such exposure banding may be donenot only with two cameras but with any larger number of cameras, each ofwhich may be set to a different exposure sensitivity, with a largernumber of cameras enabling finer gradations in exposure selectiveness.

Yet another mechanism that may be enabled by the combination of themulti-sensor mediator with multiple cameras is object tracking. One ormore cameras may be configured for a wide field of view, which mayrecord an entire scene, while another camera or cameras may track one ormore individual objects that occur within the wider field of view, andwhich may move around within the wider field of view. The trackingcameras may be configured to record particular objects of interest, suchas an active speaker, with a higher resolution, for example, and may beused for special applications such as motion-tracking input, in oneillustrative embodiment. These are some of the examples of a wide rangeof applications that are enabled or facilitated by the multi-sensormediator of the present disclosure.

FIG. 5 depicts another illustrative embodiment of a multiple sensormanagement system 500 according to another embodiment, and with agreater level of detail provided. Multiple sensor management system 500includes image sensors 501 and 502, multi-sensor mediator circuit 503,buffer random access memory (RAM) 504, and sensor controller 505, inthis illustrative embodiment. Multi-sensor mediator circuit 503 servesas one illustrative embodiment of a multi-sensor mediator component.Multi-sensor mediator circuit 503 includes a plurality of input blocks511, 513, wherein each of the input blocks comprises a video input(Data_n) port 521, a vertical synchronization (VSYNC_n) input 523, ahorizontal synchronization (HSYNC_n) input 525, and a pixel clock(PCLK_n) input 527 (where “n” refers to a particular one of the sensorinputs, e.g. n=1, 2, etc.). Multi-sensor mediator circuit 503 alsoincludes a master device bus (I²C_n) protocol interface 531 associatedwith each of the input blocks 511, 513. Each of input blocks 511, 513and their associated master device bus protocol interfaces 531 areconnected to one of the image sensors 501, 502.

Multi-sensor mediator circuit 503 further includes an output block 539,which includes a video output port 541, a vertical synchronizationoutput 543, a horizontal synchronization output 545, and a pixel clockoutput 547. Multi-sensor mediator circuit 503 also includes a slavedevice bus protocol interface 551 associated with the output block 539.Output block 539 and slave device bus protocol interface 551 areconnected to sensor controller 505, which may illustratively be a USBwebcam controller integrated circuit, for example.

Sensor controller 505 may then control the image sensors 501, 502 viathe I²C interface, by writing operating parameters into various internalregisters of the image sensors. When the image sensors are set intoimage streaming mode, they will start the recurring processing ofexposing their light sensitive pixels for a pre-set duration, convertingthe analog voltage output of each pixel into digital data, and streamingthe digital data to the multi-sensor mediator circuit 503 via thedigital video input ports 521. The multi-sensor mediator circuit 503 maythen synthesize the separate video input data streams into a compositesignal encoding composite images combining the synchronized inputs tothe different image sensors, and direct the composite signal to sensorcontroller 505, in this illustrative embodiment.

Besides the actual image data lines, the image sensors also drive thevertical synchronization (VSYNC) input 523, horizontal synchronization(HSYNC) input 525, and pixel clock (PCLK) input 527. VSYNC is use toindicate the start of each image frame, HSYNC is used to indicate thestart of each horizontal image line, and PCLK is the pixel clockindicating that there is valid data on the data lines. The image sensors501 and 502 may support a frame synchronization operation mode acrossmultiple sensors, in this illustrative embodiment. By tying the VSYNCoutput of first image sensor 501 to the synchronize input (FSIN) ofsecond image sensor 502, both image sensors 501, 502 will operatesynchronously. This feature simplifies the design requirements formulti-sensor mediator circuit 503, as well as ensuring betterperformance of the software image processing for the computing systemdecoding the information from the composite signal, as relayed by thesensor controller 505.

Video input port 521, vertical synchronization input 523, horizontalsynchronization input 525, and pixel clock input 527 of each of theinput blocks 511, 513 enable the transmission of a data signal encodingthe images recorded by the associated image sensor, to the multi-sensormediator circuit 503, in this illustrative embodiment. Similarly, videooutput port 541, vertical synchronization output 543, horizontalsynchronization output 545, and pixel clock output 547 enable thetransmission of the composite signal encoding the combined imagesrecorded by the image sensors 501, 502 to the sensor controller 505, inthis illustrative embodiment. One illustrative example of the signalsthat may be provided by these components is depicted in FIG. 6, below.

Buffer RAM 504 may be embodied in a separate component as depicted inFIG. 5, or multi-sensor mediator 503 may include its own internal bufferRAM that performs a similar function, in various illustrativeembodiments. Buffer RAM 504 may illustratively contain four logicalsections of 640 pixels, labeled A, B, C and D respectively, in thisexemplary embodiment. During image streaming, the multi-sensor mediatorcircuit 503 may perform the following steps, according to oneillustrative embodiment:

1. Write odd numbered image lines from image sensor 501 into section Aand write odd numbered image lines from image sensor 502 to section B.

2. Write even numbered image lines from image sensor 501 into section Cand write even numbered image lines from image sensor 502 to section D.

3. While data is being written into sections A and B (odd numberedline), send image data in sections C and D as a single even numberedimage line to the sensor controller 505, and while data is being writteninto sections C and D (even numbered line), send data in sections A andB as a single odd numbered image line to the sensor controller 505.

4. The composite signal has twice the resolution of the sensor inputsignals; data sent to the sensor controller 505 has to happen at twicethe rate data is received from the individual image sensors 501, 502.

For embodiments using three, four, or more coordinated sensors, theresolution is correspondingly three, four, or more times higher, and thedata rate from the multi-sensor mediator circuit 503 to the sensorcontroller 505 must be correspondingly higher. The multi-sensor mediatorcircuit 503 should generate the necessary VSYNC, HSYNC and PCLK signalsto deliver the image data to the sensor controller 505 at the requiredrate.

FIG. 6 depicts a timing diagram for the various components of eachsensor input signal 600 provided by the respective image sensors to themulti-sensor mediator, according to one illustrative embodiment. FIG. 6also depicts a timing diagram for the various components of thecomposite signal 650 provided by the multi-sensor mediator to the sensorcontroller, according to one illustrative embodiment.

As can be seen in FIG. 6, the pixel clock component of composite signal650 has twice as many cycles per cycle of the horizontal synchronizationsignal component of composite signal 650, compared with the number ofpixel clock cycles per horizontal synchronization cycles of the sensorinput data signal 600. This is indicative of the composite signalencoding multiple VGA image input signals of 640 by 480 pixels as asingle image-encoded data signal corresponding to an image of 1280 by480 pixels, that is, encoded with each of the input images of the sametime stamp being composed into a single, larger image with the originalimages spaced horizontally adjacent to each other. Other encodingprotocols may be used by a multi-sensor mediator in other examples, suchas vertically adjacent spacing of two VGA input signals, for a compositesignal encoding a data stream of 640 by 960 pixel images; or compositesignals that encode multiple images interspersed by line or by pixel, orthat encode images from three or more image sensors, for example.

FIG. 7 illustrates an example of a suitable computing system environment700 on which various embodiments may be implemented. According to oneillustrative embodiment, computing system environment 700 may beconfigured to enable the operation of a multi-sensor mediator 703 andassociated methods for multiple sensor input data synthesis, such asthose depicted in FIGS. 1-6 and described above. For example, amulti-sensor input management system that includes multiple sensors 701,702, a multi-sensor mediator 703, and a sensor controller 704, may beconnected to user input interface 760 of FIG. 7 (further describedbelow). Computing system environment 700 may be configured withcorresponding software stored on system memory 730 and running onprocessing unit 720, for decoding the composite signals and/or processedversions of the composite signals to interpret and manipulate theinformation from the separate sensor inputs, and to generate outputsbased on the composite signal. The computing system environment 700 mayillustratively be configured to provide those outputs via videointerface 790 and monitor 791, and additional components not depicted inFIG. 7 for providing modes of output such as stereo video andthree-dimensional video representations, as discussed above, forexample.

For example, various embodiments may be implemented as softwareapplications, modules, or other forms of instructions that areexecutable by computing system environment 700 and that configurecomputing system environment 700 to perform various tasks or methodsinvolved in different embodiments. A software application or moduleembodying a collocation error proofing embodiment may be developed inany of a variety of programming or scripting languages or environments.For example, it may be written in C#, F#, C++, C, Pascal, Visual Basic,Java, JavaScript, Delphi, Eiffel, Nemerle, Perl, PHP, Python, Ruby,Visual FoxPro, Lua, or any other programming language. It is alsoenvisioned that new programming languages and other forms of creatingexecutable instructions will continue to be developed, in which furtherembodiments may readily be developed.

Computing system environment 700 as depicted in FIG. 7 is only oneexample of a suitable computing environment for executing and providingoutput from various embodiments, and is not intended to suggest anylimitation as to the scope of use or functionality of the claimedsubject matter. Neither should the computing environment 700 beinterpreted as having any dependency or requirement relating to any oneor combination of components illustrated in the exemplary operatingenvironment 700.

Embodiments are operational with numerous other general purpose orspecial purpose computing system environments or configurations.Examples of well-known computing systems, environments, and/orconfigurations that may be suitable for use with various embodimentsinclude, but are not limited to, personal computers, server computers,hand-held or laptop devices, multiprocessor systems,microprocessor-based systems, set top boxes, programmable consumerelectronics, network PCs, minicomputers, mainframe computers, telephonysystems, distributed computing environments that include any of theabove systems or devices, and the like.

Embodiments may be described in the general context ofcomputer-executable instructions, such as program modules, beingexecuted by a computer. Generally, program modules include routines,programs, objects, components, data structures, etc. that performparticular tasks or implement particular abstract data types. Someembodiments are designed to be practiced in distributed computingenvironments where tasks are performed by remote processing devices thatare linked through a communications network. In a distributed computingenvironment, program modules are located in both local and remotecomputer storage media including memory storage devices. As describedherein, such executable instructions may be stored on a medium such thatthey are capable of being read and executed by one or more components ofa computing system, thereby configuring the computing system with newcapabilities.

With reference to FIG. 7, an exemplary system for implementing someembodiments includes a general-purpose computing device in the form of acomputer 710. Components of computer 710 may include, but are notlimited to, a processing unit 720, a system memory 730, and a system bus721 that couples various system components including the system memoryto the processing unit 720. The system bus 721 may be any of severaltypes of bus structures including a memory bus or memory controller, aperipheral bus, and a local bus using any of a variety of busarchitectures. By way of example, and not limitation, such architecturesinclude Industry Standard Architecture (ISA) bus, Micro ChannelArchitecture (MCA) bus, Enhanced ISA (EISA) bus, Video ElectronicsStandards Association (VESA) local bus, and Peripheral ComponentInterconnect (PCI) bus also known as Mezzanine bus.

Computer 710 typically includes a variety of computer readable media.Computer readable media can be any available media that can be accessedby computer 710 and includes both volatile and nonvolatile media,removable and non-removable media. By way of example, and notlimitation, computer readable media may comprise computer storage mediaand communication media. Computer storage media includes both volatileand nonvolatile, removable and non-removable media implemented in anymethod or technology for storage of information such as computerreadable instructions, data structures, program modules or other data.Computer storage media includes, but is not limited to, RAM, ROM,EEPROM, flash memory or other memory technology, CD-ROM, digitalversatile disks (DVD) or other optical disk storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium which can be used to store the desired informationand which can be accessed by computer 710. Communication media typicallyembodies computer readable instructions, data structures, programmodules or other data in a modulated data signal such as a carrier waveor other transport mechanism and includes any information deliverymedia. The term “modulated data signal” means a signal that has one ormore of its characteristics set or changed in such a manner as to encodeinformation in the signal. By way of example, and not limitation,communication media includes wired media such as a wired network ordirect-wired connection, and wireless media such as acoustic, RF,infrared and other wireless media. Combinations of any of the aboveshould also be included within the scope of computer readable media.

The system memory 730 includes computer storage media in the form ofvolatile and/or nonvolatile memory such as read only memory (ROM) 731and random access memory (RAM) 732. A basic input/output system 733(BIOS), containing the basic routines that help to transfer informationbetween elements within computer 710, such as during start-up, istypically stored in ROM 731. RAM 732 typically contains data and/orprogram modules that are immediately accessible to and/or presentlybeing operated on by processing unit 720. By way of example, and notlimitation, FIG. 7 illustrates operating system 734, applicationprograms 735, other program modules 736, and program data 737.

The computer 710 may also include other removable/non-removablevolatile/nonvolatile computer storage media. By way of example only,FIG. 7 illustrates a hard disk drive 741 that reads from or writes tonon-removable, nonvolatile magnetic media, a magnetic disk drive 751that reads from or writes to a removable, nonvolatile magnetic disk 752,and an optical disk drive 755 that reads from or writes to a removable,nonvolatile optical disk 756 such as a CD ROM or other optical media.Other removable/non-removable, volatile/nonvolatile computer storagemedia that can be used in the exemplary operating environment include,but are not limited to, magnetic tape cassettes, flash memory cards,digital versatile disks, digital video tape, solid state RAM, solidstate ROM, and the like. The hard disk drive 741 is typically connectedto the system bus 721 through a non-removable memory interface such asinterface 740, and magnetic disk drive 751 and optical disk drive 755are typically connected to the system bus 721 by a removable memoryinterface, such as interface 750.

The drives and their associated computer storage media discussed aboveand illustrated in FIG. 7, provide storage of computer readableinstructions, data structures, program modules and other data for thecomputer 710. In FIG. 7, for example, hard disk drive 741 is illustratedas storing operating system 744, application programs 745, other programmodules 746, and program data 747. Note that these components can eitherbe the same as or different from operating system 734, applicationprograms 735, other program modules 736, and program data 737. Operatingsystem 744, application programs 745, other program modules 746, andprogram data 747 are given different numbers here to illustrate that, ata minimum, they are different copies.

A user may enter commands and information into the computer 710 throughinput devices such as a keyboard 762, a microphone 763, and a pointingdevice 761, such as a mouse, trackball or touch pad. Other input devices(not shown) may include a joystick, game pad, satellite dish, scanner,or the like. These and other input devices are often connected to theprocessing unit 720 through a user input interface 760 that is coupledto the system bus, but may be connected by other interface and busstructures, such as a parallel port, game port or a universal serial bus(USB). A monitor 791 or other type of display device is also connectedto the system bus 721 via an interface, such as a video interface 790.In addition to the monitor, computers may also include other peripheraloutput devices such as speakers 797 and printer 796, which may beconnected through an output peripheral interface 795.

The computer 710 is operated in a networked environment using logicalconnections to one or more remote computers, such as a remote computer780. The remote computer 780 may be a personal computer, a hand-helddevice, a server, a router, a network PC, a peer device or other commonnetwork node, and typically includes many or all of the elementsdescribed above relative to the computer 710. The logical connectionsdepicted in FIG. 7 include a local area network (LAN) 771 and a widearea network (WAN) 773, but may also include other networks. Suchnetworking environments are commonplace in offices, enterprise-widecomputer networks, intranets and the Internet.

When used in a LAN networking environment, the computer 710 is connectedto the LAN 771 through a network interface or adapter 770. When used ina WAN networking environment, the computer 710 typically includes amodem 772 or other means for establishing communications over the WAN773, such as the Internet. The modem 772, which may be internal orexternal, may be connected to the system bus 721 via the user inputinterface 760, or other appropriate mechanism. In a networkedenvironment, program modules depicted relative to the computer 710, orportions thereof, may be stored in the remote memory storage device. Byway of example, and not limitation, FIG. 7 illustrates remoteapplication programs 785 as residing on remote computer 780. It will beappreciated that the network connections shown are exemplary and othermeans of establishing a communications link between the computers may beused.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims. As a particular example, whilethe terms “computer”, “computing device”, or “computing system” mayherein sometimes be used alone for convenience, it is well understoodthat each of these could refer to any computing device, computingsystem, computing environment, mobile device, or other informationprocessing component or context, and is not limited to any individualinterpretation. As another illustrative example, references are madeherein to different components being communicatively connected with eachother, and this may refer either to a wired connection, a wirelessconnection, or any other means by which different components may be ableto communicate information from one to another. As yet anotherparticular example, while many embodiments are presented withillustrative elements that are widely familiar at the time of filing thepatent application, it is envisioned that many new innovations incomputing technology will affect elements of different embodiments, insuch aspects as user interfaces, user input methods, computingenvironments, and computing methods, and that the elements defined bythe claims may be embodied according to these and other innovativeadvances while still remaining consistent with and encompassed by theelements defined by the claims herein.

What is claimed is:
 1. A method comprising: obtaining input from aplurality of image sensors including at least a first sensor to capturea scene and a second sensor to track objects within the scene; combiningthe inputs from the plurality of image sensors to form a compositesignal that has a resolution that is a multiple of a resolution ofimages obtained via one or more of the plurality of image sensors andencodes the scene from the first sensor and tracking data from thesecond sensor in the composite signal; and communicating the compositesignal to an image sensor controller to cause the image sensorcontroller to generate an output image based at least in part upon thecomposite signal.
 2. The method of claim 1, wherein the output image hasa three-dimensional appearance.
 3. The method of claim 1, wherein thefirst sensor comprises a camera configured to capture a wide field ofview.
 4. The method of claim 1, wherein the second sensor comprises atracking camera.
 5. The method of claim 1, wherein at least one of theplurality of image sensors is used to obtain motion-tracking input. 6.The method of claim 5, wherein the composite signal is configured toprovide the motion-tracking input to a controller to cause thecontroller to produce a processed signal for input to a computingdevice.
 7. The method of claim 1, wherein the composite signal isprocessed to form a universal serial bus (USB) protocol signal forproviding input from the plurality of image sensors to a computingdevice.
 8. The method of claim 1, wherein the plurality of image sensorsenable object tracking by detection of distance differences of objectsfrom the plurality of image sensors.
 9. The method of claim 1, whereinat least one of the plurality of image sensors is provided as anexternal sensor connected to a computing device that uses informationprovided by the plurality of image sensors.
 10. The method of claim 1,wherein at least one of the plurality of image sensors is includedwithin a computing device that uses information provided by theplurality of image sensors.
 11. The method of claim 1, wherein theplurality of image sensors enable facial recognition within the capturedscene.
 12. One or more computer-readable storage media storinginstructions that when executed by a computing device, cause thecomputing device to perform operations to process input from a pluralityof image sensors including: obtaining inputs from the plurality of imagesensors including at least a first camera to capture a scene and asecond camera to track objects within the scene; combining the inputsfrom the plurality of image sensors to form a composite signal that hasa resolution that is a multiple of a resolution of images obtained viaone or more of the plurality of image sensors and encodes the scene fromthe first camera and tracking data from the second camera in thecomposite signal; processing the composite signal to produce a processedsignal in the form of a universal serial bus (USB) protocol signal; andusing the processed signal that reflects the inputs from the pluralityof image sensors to generate a response to the inputs by the computingdevice.
 13. One or more computer-readable storage media as recited inclaim 12, wherein the input from the plurality of image sensorscomprises motion-tracking input captured by the plurality of imagesensors.
 14. One or more computer-readable storage media as recited inclaim 12, wherein the response to the inputs by the computing devicecomprises outputting an image for display based on the processed signal.15. One or more computer-readable storage media as recited in claim 12,wherein the response to the inputs by the computing device comprisesrendering an output image having a three-dimensional appearance based onthe processed signal.
 16. One or more computer-readable storage media asrecited in claim 12, wherein the response to the inputs by the computingdevice comprises performing facial recognition to identify one or moreindividuals within the scene.
 17. A computing device comprising: aprocessing unit; an input interface adapted to obtain inputs from aplurality of image sensors including a tracking camera to track objectswithin a scene; a multi-sensor mediator configured to combine the inputsfrom the plurality of image sensors to form a composite signal that hasa resolution that is a multiple of a resolution of images obtained viaone or more of the plurality of image sensors and encodes a combinationof information from the plurality of image sensors including trackingdata from the tracking camera; and a sensor controller configured to:process the composite signal provided by the multi-sensor mediator toproduce a processed signal in the form of a universal serial bus (USB)protocol signal; and provide the processed signal to the processing unitto enable the computing device to generate a response to the inputs. 18.The computing device as recited in claim 17, further comprising a videointerface configured to output an image rendered in response to theinputs for display on a display device connected to the video interface.19. The computing device as recited in claim 17, further comprising atleast one of the plurality of image sensors included as a component ofthe computing device.